Hydraulic actuator and lock unit



Aug. 16, 1949.

A. E. KREMILLER HYDRAULIC ACTUATOR AND LOCK UNIT 3 Sheets-Sheet 1 Filed Feb. 19, 1946 I 4 8- A. E. KREMILLER ,479,

HYDRAULIC ACTUATOR AND LOCK UNIT Filed Feb. 19, 1946 3 Sheets-Sheet 2 3/ 2 1 1;- 25 2 48/ 50 49 H 2 l 3 l 7 47 r '7 J 30 ll 23 20 P I 3 T q E #flrfiu/Pi MEN/115R 1949. A. E. KREM ILLER 2,479,169

7 HYDRAULIC ACTUATOR AND LOCK UNIT Filed Feb. 19, 1946 3 Sheets-Sheet 3 Patented Aug. 16, 1949 UN [TED 1 PAT ENT F F 1 CE u 2,479,169 7 I HYDRAULIC ACTUATOR AND LOCKUNIT Arthur ninremiuer, Glendale, Calif., assignor to Adel Precision of California Products Corp., a corporation Application February 19, 1946, Serial No. 648,688

Claims.

This invention has for an object the provision of a self contained hydraulic lock unit which may be installed as a link in any train of reciprocable mechanism for operatinga control element, to operate as a ratchet throughout infinitely small increments of movement in either direction thereby affording a nicetyof control of said ele-' ment and assuring the holding thereof in any position'to which it is moved. 7 7 An object of the inventionis to provide a hydrauliclock mechanism, which will prevent the transmissio'ncf any external, forces imposed on the driven end'cf a 'reciprocable mechanism'iro'm being transmitted to thedriving end so thatthe driven end and element operated thereby will be hydraulically locked inany position towhich itis moved by said reciprocable mechanism; Still another object of the invention is to provide a device of the above character "which includes a novel means for maintaining the fluid contained therein at a substantially uniform initial pressure regardless of thermalchanges and minorleakage.

A still further object of the invention is to provide' a device of the above character in which any depletionof the volume of fluid is indicated ex? ternally of the device; r u

1 Still another object of'tlie invention is to provide a device of thef-above'character in which means'is provided for rendering the pressure cre ating meansv inoperative during the filling or refilling operation. f f I ,Inithe following specification there is disclosed bywayof example a manner in" which the above and, such other desirable 'fobjects; as. may subse;

quently appear maybe reali'z'ed in practice, refer ence being had to the accompanying drawings in V ichw .1. Fig. 1 is a sideelevation v.of one form ofhy" draulic lock valve embodying the present inveni n; c

Fig. 2 is an end elevation of the device shown in Fi 1;

-Fig. 3 is asectional view takensubstantially on the line 3-3 of Fig. 2; r v

Fig. '4 is a fragmentary sectional view corre-- spending to Fig. 3 showing th d e in one extreme position;

Fig. 5 is a schematic view ofthe device shownin Fig. 1, incorporated in a control mechanism; Fig. 6 is a sectional view taken on the line 6-6 Fig.1 '7 is an exploded. valve assembly; w

view or thefpiston a d- Fig. 8 is aisectional viewof the device taken on the line 8.-8 of Fig.2; b 1

Fig. 9 is a cross sectional view taken on the line 99ofFig.3;

Fig. 10 is a perspective view. of the assembled piston valve unit. t I

As'shown in the accompanying drawings, one embodiment of this invention includes a body member I having a series of transverse holes 2 for'the reception of bolts} by which it maybe mounted to any suitable. support, such as a bracket 4. The bodymembe'r constitutes a cylin der provided with a'longitudinally extending bore 5 the ends of which 'are'closed by end-plates 6 secured thereto with screws I. Preferably the plates 6 are provided with grooves} in whichare mounted, suitable [pressure-responsive sealing rings 9 to prevent the escape of fluid. j Mounted for reciprocationin the bore 5 is a double-headed piston member Phaving opposedlilre piston heads wand ll provided with pres sure-responsive sealing rings 12 and I3, respec tively. These, piston heads are provided with axial bores l2 and I3 adapted to receive reciprocable poppet valve members It and lithe, stems of which are provided with sealing rings I6 and H. The bores within the piston, near the outerends of the heads are enlarged toprovide valve seats l8 and I8 against which the valve' members seat. While, as shown, there are no spring elements to maintain the valves 14 and l5 'in,normally s eated position, such springs may be used without departure from the invention. Intermediate its ends the piston member P is cover plates 2| and 22 which are held in place by snap rings 23 and 24' engageable with suitable grooves in the ends of. the pistons H and I0,

respectively.

The piston P is also prcvided with a recess 24 which is diametrically'opposite the recess 20, but which is of less depth than recess 20 so that it does not intersect the bores containing the valves l 4 and [5. The recesses 20 and 24 define a web 25 connecting the piston heads HI and II. 'Extending through theweb member 25 is a port 26 for connecting th evalve bores l0 and l I.

The recesses 20*and 24 are open to the atmosphere through an opening 25 in the body member I, said opening being in direct communication with that portion of the bore 5 which is between the piston heads Ill and I I.

The body member I intermediate its ends is provided with a pair of upstanding lugs 21 and 28 which are bored to receive a bolt 29. Pivotally mounted on the bolt 29 with interposition of a ball bearing member 30 is a driving lever 3| having a rounded lower end 32 extending through the opening 25 in the body I for operating the valves.

I4 and I 5 as well as moving the piston responsive to rocking of the lever 3|. that the recess 23 is somewhat wider than the rounded end 32 so that a small amount of play or relative movement between the end 32 and the piston P will take place under operating conditions such will be hereinafter fully described.

Moreover, it should be noted with reference to Figs. 6, 7 and that the valve-receiving bore I2 and I3 in the piston heads I0 and II extend partly into the web so that only small segments of the inner ends of the stems of the valves I4 and I5 are exposed in the recess 20 for contact with the rounded end 32 of the driving lever 3I. Therefore only small portions of the opposite curved surfaces of the end 32 are disposed to contact the valve stems whereas the major portions of said curved surfaces are disposed to abut the end walls of the recess 20, that is, the inner ends of the heads I0 and II. The clearance between the curved surfaces of the rounded end 32 and the inner end faces of the heads I0 and II as well as between the inner ends of the stems of valves I4 and I5 and the opposite surfaces of the end 32 is such that the piston unit may hif relative to said d 32. or v ce ver sufficient to center the piston unit with respect to said end and therefore allow the valves I 4 and I5 to be seated to hydraulically lock the piston P and associated elements a ainst. movement reponsiv t rce applied to h mechanism oth r than hro h ntentional manip ation of th driving lever 3I, all as will, be hereinafter fully described.

A- driving lever 33 similar to lever 3| is pivoted on the bolt 29 and has a. lower end 35 which extends into the recess 24 and is shaped to co pletely fill that recess so that no play will take place in the direction of movement of the lever 33 and piston F. From, the foregoing it. will be appreciated that as the piston P reciprocates in the bore 5 responsive to'movement of the driving lever 3| the lever 33 will be moved correspondingly about the bolt 29 as a fulcrum.

The body member I is provided. with a second cylinder portion in the bore 36 on which" is mounted a spring-pressed piston P including a piston head 36 which latter carried a pressureresponsive sealing ring 39.. The. bore 36 is. closed at one end by one of the plates 6 which'is. provided with a second sealing ring 40. At its other end the bore 36 is formed with a reduced diameter portion 3! through which the piston P extends. A compression spring 42 surrounds the. piston P with one end bearing against the piston head 38. The piston P extends through the portion 4| and is provided with a reduced diameter threaded portion 43 carrying a lock nut 44.. The body memberl adjacent the end of the bore 33 adjacent the cover plate 6 is provided with a port 45 which affords communication of one end of the bore 5 with the bore 36, The bore 36 is provided with a groove which accommodates a snap ring 46 for limiting the movement of the piston head It should be noted- 4 under the influence of the spring 42 to a position short of closing the port 45.

Filler holes 41 and 48 normally closed by means of screw plugs 49 and 50 are provided at the ends of the body I for filling the two cylinder bores 5 and 36. The main purpose of the piston P and associated elements is to provide a means for maintaining the fluid in the device under constant pressure and assure the proper seating of valves I4 and I 5. When the device is to be filled 0r refilled the nut 44 is screwed up on the threaded portion 43 drawing the piston back against the pressure ,of the spring 42. The cylinder cavities are then filled through the filler holes 41 and 48, the plugs 49 and 5!] replaced, and the nut 44 is backed off, allowing the piston to exert the pressure of the spring 42 against the fluid.

Any changes in the volume of the fluid by reason of thermal changes or by reason of minor leakage will be compensated for by the action of the spring pressed piston P so that an initial pressure on the fluid and the proper volume of fluid within the bore 5 are maintained. When the piston P' is disposed at a point which indicates that the head 38 is either in contact with or close to the stop ring 45, the piston head may be Withdrawn by the stop nut 44 and additional iluid added through the filler holes 41 and 48, as above described. Thus the piston P indicates by its position the amount of fluid in the device,

Referring now to Fig. 5 there is shown diagrammatically a typical installation of the device and a train of mechanism for operating a carburetor, or the like, designated by the numeral 5 y orces derived from r m y l a perating lever 52. A rod 53 connects the lever 52 with the drive lever 3| and rod 5 con the driven lev r 33 ith an p rating arm on th ev ce 5| to be. opera ed,

It w l e no ed ha wh n th per n le er 52 is tu ned about its ul rum in a c o i i ect on, the dr v ever 3| co ne t d h eto throu h. the rod 53, will be turned upon the pivot bolt 29 n a ounterclockwise. direction re ulta t movem nt of the piston P to the ri ht as v ewed in F 7- The first mo ement. f th nd 32 oi the lever 3| will unseat the valve 14 and permit the flow of fluid throug the open n s in th plate 22, p s the valv seat l8. thr u t e. por 26 i to b 3 wh re it. wi l unseat the valve l5 and pa s o the. oppo i e end of. h cylinder, Incident to the opening of the valve I4, the end 32 throu h conta t with th head I0 w ll mo the pist n B to. the right. This movement of t e. pist nw ll. e c a simultaneous mov m nt of he v r 33. q a n ext nt o th mov ment imparted to the piston by the movement of the lever 3| whereby the rod 54 will move the operating arm 55 and control device 5|. Movement of the operating lever 52 in the opposite direction will cause the piston P to move to the left and also move the driven lever 33 and the operating arm 55 of the device 5I to the right.

Upon cessation of movement of the operating lever-52, the piston P is stopped and as the inner ends of the stems of the valves I4 and I5 are. expose to atmosphe c p ess re throug h ece 0 a d t e p n .5 n th body while the valves themselves are exposed to the fluid pressure created in both ends of the bore 5 by the spring loaded piston P, both valves. will be instantly seated. In thus seating, the valve stem of the valve which is in contact with the, end 32 o ver .31, ll push aga n t sa d en so th the piston is bodily shifted slightly, sufiii ciently to center itself with respect to said end whereby said lever will not interfere with the pressure seating of said valves. This action is made possible by the slight clearance between the inner ends of the piston heads l and I l and the curved end 32 opposed to said inner ends. When the valves l4 and I5 are seated following a given operation of the operating lever 52 and consequent, response of the piston P and driven elements which operate the controlled device 5|, the piston P is hydraulically locked and therefore the entire mechanism becomes locked against movement responsive to any externally applied force, that is, any force other than transmitted through intentional operation of the operating lever 52. In this manner it is assured that the control arm 55 of the device 5| operated through the mechanism hereof will be maintained in any position into which it has been moved and may be moved out of said position only responsive to operation of the operating lever 52 and the driving lever 3|.

It is now apparent that should a force other than derived from movement of the operating lever 52 be applied so as to tend to move the driven lever 33 and the control arm 55 it will be inefiective to move suchparts due to the fact that the piston P is hydraulically locked and no play is permitted by the operative connection of said driven lever 33 and said piston, thereby assurin that the control arm 55 of the device 5| will be positively held in the selected position into which it is moved.

With the means of this invention it is possible to accurately control and operate a device or control element with provision for positively locking said device or element in any position within the range of itsmovement in either direction, there being a positive locking action provided with much smaller increments of movement than possible with mechanical-ratchet or similar mechanical means.

While I have shown and described a specific embodiment of my invention I do not limit myself to the exact details of construction set forth, and the invention embraces such changes, modifications and equivalents of the parts and their formation and arrangement as come within the purview of the appended claims.

I claim:

1. In a hydraulic actuator and lock unit, a

ing the transfer offluid from one end of the cylinder to the other wherebythe piston may be reciprocated, a drive lever fulcrumed on said cylinder with one end disposed for contact with said piston for reciprocating it, a driven lever having one end disposed to contact said piston and moving responsive to movement of said piston, and valve means controlling said passage constructed and arranged; to be unseated and open said passage responsive to operation of said drive, lever, and to be seated by the pressure of the fluid in said cylinder and close said passage incident to the cessationof operation of said drive lever.

'3. In a hydraulic actuator and lock unit, a closed cylinder containing a hydraulic fluid, a piston reciprocable in said cylinder, means for maintaining the liquid. in. said cylinder under pressure, a by-pass passage in said piston affording the transfer of fluid from one end of the cylinder to the other whereby the piston may be reciprocated,;a drive lever having one end disposed'in the cylinder and in lost motion connection with said piston and operable for reciprocating said piston,a driven lever fulcrumed On the cylinder with one 'end directly connected to the piston and operating responsive to movement of said piston, and valve means for controlling said passage being normally seated by the pressure of the fluid in said cylinder and constructed and arranged to be unseated responsive to initial movement of said drive lever and responsive to flow through said passage responsive to initial movement of said piston, and being seated by the pressure in said cylinder so as to close said passage and hydraulically lock said piston against movement incident to cessation of operation of said drive lever.

4. In a hydraulic actuator and lock unit, a closed cylinder adapted to contain a hydraulic fluid, a piston reciprocable in said cylinder, means for maintaining the liquid in said cylinder under pressure, a by-pass passage in said piston aflording the transfer of fluid from one end of the cylinder to the other whereby the piston may be reciprocated, a drive lever for reciprocating said piston, said piston having a recess between its ends into which one end of said drive lever is cylinder adapted to contain a hydraulic fluid, a

piston reciprocable in said cylinder and havin a fluid passage afiording the transfer of fluid from one end of the cylinder to the other whereby the piston may be reciprocated, a drive lever fulcrumed on said cylinder with one end disposed to directly contact the piston for reciprocating it, a driven lever fulcrumed on said cylinder with one end disposed for contact with the piston for movement responsive to the movement of said piston, means for maintaining the fluid in said cylinder under pressure, and valve means for controlling the flow through said passage constructed and arranged to be unseated and open said passage responsive to the initial operation of said drive lever and to be seated by the pressure of the fluid in said cylinder so as to close said passage and hydraulically lock said piston against movement, upon cessation of operation of said drive lever.

2. In a hydraulic actuator and lock unit, a closed cylinder adapted to contain a hydraulic fluid, a piston reciprocable in said cylinder, means for maintaining the fluid in said cylinder under pressure, a by-pass passage in said piston affordextended so that it will contact opposite walls of the recess and move the piston upon the rocking of said lever about its fulcrum, a driven lever mechanically connected with and operating responsive to movement of said piston, a pair of valves for controlling said passage having stems arranged to protrude into said recess when said valves are seated, there being an opening in said cylinder through which said levers extend and which affords communication of said recess with the atmosphere whereby said stems are exposed to atmospheric pressure, said valves being exposed to and seated by the pressure of the fluid in said cylinder, said end of said drive lever and said recess and said stems being constructed and arranged so that upon initial movement of said lever one of said valves will be unseated and open said passage to flow of fluid against the other valve to thereby unseat the other so that fluid will be transferred through said passage from one of the ends of the cylinder to the other on movement of said piston, said valves being seated by the pressure of the fluid in said cylinder and closing said passage and hydraulically locking the piston against movement incident to cessation of driving movement of said drive lever.

5. In a hydraulic actuator and lock unit, a cylinder closed at its ends and having an opening between its ends afiording communication of the interior of the-cylinderwith the atmosphere, a. piston unit reciprocable inv said cylinder and havmg recesseso'pp'os-ite sides between its ends, which recesses are in registration with said openmg in all positions of said piston unit, said piston unit having coaxial bores extending from opposite ends thereof with their inner ends opening into one of said recesses, valve seats in said bores, valve members arranged to seat on said seats in a direction toward said one recess, stems on said valve members sealing the inner ends of said bores and having a slight protrusion into said one recess when the valve members are seated, at driving. lever pivoted on said cylinder with one end extending through said opening and into said recess for unseatfng said valve members and moving said piston unit, said end of said lever having a width such that the piston unit and said end are subject to limited relative movement with said end disposed to contact one or the other of said stems and open one. or the other of the valve members depending on the direction of movement of said lever and thereafter to move said piston unit as the movement of the lever continues, said cylinder being adapted to contain a liquid between its end and the ends of said piston unit to hydraulically hold the piston against movement when the valve members are closed, said piston unit having therein a connecting passage between said coaxial bores affordingthe passage of the liquid from the bore in which the valve is opened by said end of said lever into the other bore so as to open the valve in said other bore, a driven lever pivoted on said cylinder with one end disposed in the other recess so that the driven lever will be rocked responsive to movement of said piston, and means for creating an initial pres? sure of the liquid in said cylinder such that when movement of the driving lever is stopped the valve members will be seated due to the ends 01' the stems being exposed to atmospheric pressure in said one recess While the valve members are exposed to the pressure of the liquid in said cylinder.

- ARTHUR E. KREMILLER.

REFERENCES CITED I The following references are of record in the file of this patent:

UNITED STATES PATENTS 

